According to Dr. Rene Cailliet, an emeritus professor of Physical Medicine and Rehabilitation at the David Geffen School of Medicine at UCLA and the author of numerous books on musculoskeletal medicine, anterior head carriage can add up to 30 pounds of leverage on your cervical spine, which can pull your spine out of alignment. Dr. Cailliet states that anterior head carriage can lead to the loss of 30 percent of your lung's vital capacity (the total amount of air you can expel from your lungs after a maximum inspiration). Anterior head carriage-related loss of vital capacity is due to your loss of cervical lordosis or neck curvature, which negates the action of your hyoid muscles, especially your inferior hyoid muscle, which is responsible for elevating your first rib during a deep breath in. Postural exercises are an effective way to restore your normal neck curvature and regain your lung vital capacity.